Many different kinds of such floor constructions are known to the art.
One example of such known floor constructions is an installation floor retailed under the designation Modell 10 and 15 by "Donn Scandinavia", Sigtuna, Sweden. This known floor construction comprises a plurality of spot footings provided with adjustable lock nuts for making vertical height adjustments, these spot footings being placed so that the corners of each slab forming a floor surface rest on four of said footings. Each of these slabs comprises a high-density intermediate laminated body having heat-galvanized metal plates fixed to the top and bottom surfaces thereof, in order to provide a self-supporting and load-bearing slab. In addition, it is necessary to strengthen the edges of the slabs with the aid of a U-section sunk into the edges of the slab. The slabs can be provided with a surface covering of synthetic resin laminates, vinyl squares, needle felt or some other soft covering material.
In order to be able to reduce the load-bearing requirements of the slab per se, so that weaker slabs can be used, it has been proposed that short joists are arranged between mutually adjacent spot footings, such that a group of four joists will form a support for the four edge portions of a slab. Each such short joist must be attached or fastened at its end surfaces to a respective spot footing.
Another known floor construction of this kind is one sold by ASEA, Vaster.ang.s, Sweden, under the designation KAFAK HELLANGOLV. This floor construction comprises a plurality of mutually parallel elongated, longitudinally extending first joists and a plurality of mutually parallel second joists similar to said first joists and extending at right angles thereto, the mutually perpendicularly extending and mutually intersecting first and second joists defining square and/or elongate rectangular cavities which are covered by a single floor slab or a plurality of floor slabs. These slabs are arranged and dimensioned so that two mutually opposing side edges of a slab rest against and are supported by the upper surfaces of the edge sections of adjacent joists.
The longitudinally extending joists are supported on vertically adjustable spot footings.